jsonstatslice

#!/usr/bin/env node

var
	argv=require("yargs")
		.version()
		.usage("Usage:\n  $0 [input filename] [output filename] -f [filter]\n  $0 < [input] > [output] -f [filter] -t")
		.example("$0 oecd.json oecd-subset.json -f \"area\"=\"DE\",\"year\"=\"2014\"", "converts JSON-stat file oecd.json into a new JSON-stat file (oecd-subset.json).")
		.example("$0 < oecd.json > oecd-subset.json -f \"area\"=\"DE\",\"year\"=\"2014\" -t", "converts JSON-stat stream oecd.json into a new JSON-stat stream (oecd-subset.json).")
		.alias("f", "filter")
		.describe("f", "Filter string (for example: area=DE,year=2014)")
		.boolean("m")
		.alias("m", "modify")
		.describe("m", "Modify value and status type")
		.boolean("o")
		.alias("o", "ovalue")
		.describe("o", "Type of value: object instead of array")
		.boolean("s")
		.alias("s", "ostatus")
		.describe("s", "Type of status: object instead of array")
		.boolean("t")
		.alias("t", "stream")
		.describe("t", "Enable the stream interface")
		.help("h")
		.alias("h", "help")
		.argv
	,
	inout=require("./inout"),


		arr2obj=function(o,p){ //o object p property
			var ret={};
			if(Object.prototype.toString.call(o[p]) === '[object Array]'){
				o[p].forEach(function(e,i){
					if(e!==null){
						ret[String(i)]=e;
					}
				});
				return ret;
			}
			return o[p];
		},

		obj2arr=function(o,p){	//o object p property
			var
				v,
				ret=[],
				i=o.size.reduce(function(a, b){ return a * b;});
			;

			if(typeof o[p] === 'object' && Object.prototype.toString.call(o[p]) !== '[object Array]'){
				for(;i--;){
					v=o[p][String(i)];
					ret[i]=typeof v!=="undefined" ? v : null;
				}
				return ret;
			}

			return o[p];
		},

		modify=function(tree, attr){
	    var
	      arg=(attr==="value") ? argv.ovalue : argv.ostatus,
	      typ=Object.prototype.toString.call(tree[attr])
	    ;

	    if(
	      //value/status is array but object was requested
	      (typ==="[object Array]" && arg)
	      ||
	      //value/status is object but array was requested
	      (typ!=="[object Array]" && !arg)
	    ){
	      var newcont=arg ? arr2obj(tree, attr) : obj2arr(tree, attr);
	      delete tree[attr];
	      tree[attr]=newcont;
	    }
	  },

		stringify=function(json){
			var tree=json.__tree__;

			//if v<2.0 convert to 2.0
			if(!tree.hasOwnProperty("id")){
				tree.version="2.0";
				if(!tree.hasOwnProperty("class")){
					tree.class="dataset";
				}

				tree.id=tree.dimension.id;
				tree.size=tree.dimension.size;
				delete tree.dimension.id;
				delete tree.dimension.size;

				if(tree.dimension.hasOwnProperty("role")){
					tree.role=tree.dimension.role;
					delete tree.dimension.role;
				}
			}

			if(tree.hasOwnProperty("status") && tree.status===null){
				delete tree.status;
			}

			if(tree.hasOwnProperty("role")){
				delete tree.role.classification;

				["geo", "time", "metric"].forEach(function(e){
					if(tree.role[e]===null){
						delete tree.role[e];
					}
				});
			}

			if(argv.modify){
		    modify(tree, "value");
		    if(tree.hasOwnProperty("status")){
		      modify(tree, "status");
		    }
		  }

			return JSON.stringify(tree);
		},

		callback=function(contents){
			var
				arrfil,
				subset,
				filter=argv.filter
			;

			//filter is not required: if not specified (no -f or -f without string) don't slice
			if(!filter || filter===true){
				return stringify( inout.dataset(contents) );
			}

			if(filter.indexOf("=")===-1){
				console.error("Error: The filter has not been specified correctly (missing =).");
				process.exit(1);
			}

			arrfil=filter.split(",").map(function(e){
				return e.split("=");
			});

			subset=inout.dataset(contents).Slice(arrfil);
			if(subset===null){
				console.error("Error: The input does not containt valid JSON-stat or the filters are not valid.");
				process.exit(1);
			}else{
				return stringify(subset);
			}
		}
	;

	inout.main(argv, callback, true);